Blount disease in a case of Prader-Willi syndrome: why is it not as prevalent as in obesity without Prader-Willi syndrome?

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic disorder causing multisystem abnormalities with obesity. Obesity is a well established cause of Blount disease.

METHODS

A 7-year-old girl with PWS presented with genu varum of the left knee with deformity of the proximal medial tibial condyle, which was consistent with Blount disease.

RESULTS

A lateral physeal stapling and subsequent osteotomy for the left proximal tibia and fibula were performed with improved anatomical alignment.

CONCLUSION

Blount disease has not been reported in the literature in association with PWS despite excessive obesity.